This is equally as dangerous since the harder reads could have the easiest questions.... a lot of the time they do and you are quite literally throwing away easy points for hard/ time consuming questions. A harder read may take you 45-60 seconds more than an easy read but I promise you 6 harder question stems will take you 60 seconds + than 6 easy question stems.
The best strategy here is to figure out what works for you. For some, reading the passages faster and REALLY focusing on the main idea and tone is what helps the most.
For me, even when I take all the time in the world reading the passage a second time (after taking the exam), a lot of the time I still get the same questions wrong I did the first time. A matter of fact, if I can skim and get the main idea and tone down, I tend to do better than if I sit there and try to soak in the details because a lot of questions are based around the big picture. The details can sometimes throw you into a trap answer based in details like direct wording.
For passages heavy on names and theories you have to skim for main idea, passage and highlighted differences in these people/theories.
Do not go guessing on an entire passage. DO NOT do this. It is not worth the gamble. Hell, a lot of the time it is easy to narrow every answer down to 2. You go from getting 1/2 the questions right to 1/4 right off the bat and probably saved yourself relatively no time than if you had skimmed and narrowed.